Managing Forests Under Climate Change: Trade-Offs Between Species Transition, Growth, and Carbon Storage in Germany

Due to climate change, forest growth conditions are changing and may become unfavorable for the tree species currently growing in different regions across the EU. Forest managers can actively plant trees that are better adapted not only to current site conditions but also to those expected in the future. Given the long rotation periods in forestry, consideration of climate projections up to 2100 is crucial. In this paper, we use the Global Forest Model (G4M) to project the future of German forests under different climate pathways (RCP2.6, RCP4.5, RCP6.0, and RCP8.5) and management alternatives (Economic, Societal, and Conservation). Utilizing spatially explicit forest cover and biomass maps with climate and soil data, G4M simulates forest dynamics including species distributions, productivity, growth, and carbon stocks. Our findings reveal substantial variations in forest composition, productivity, and carbon accumulation from growth across the scenarios. The Conservation management alternative, emphasizing broadleaved species and extended rotation times, notably enhances carbon stocks under moderate climate pathways. In contrast, the Economic alternative, focusing on wood harvest maximization, maintains current forest stocks under moderate climate pathways while adapting species composition to optimize productivity. These projections underscore the critical influence of management decisions on species composition, growth, and carbon storage, highlighting the need for adaptive strategies in response to climate change. Our study contributes to the ongoing dialogue on sustainable forest management by providing a comprehensive analysis of future forest dynamics under varying environmental conditions and management regimes.